Improvement in nails



l. 'LOWENSUHFL Nails.

N0.148,721, Pat'entdrMarchlLlSM.

`ATENT FFICEQ JOSEPH LOWENSOHN, OF BERLIN, PRUSSIA.

IMPROVEMENT' IN NAILS.

Specification forming pa'rt of Letters Patent No. 148,721, dated March17, 1874; application lecl February 26, 1874.

To all lwhom it may concern.:

Be it known that I, JOSEPH LOWENSOHN, of Berlin, Prussia, have inventeda new and useful Improvement in ScrewNails; and I do hereby declare thefollowing to be a full, clear, and exact description thereof, which willenable those skilled in the art to make and use the saine, referencebeing had to the accompanying drawing, forming part of thisspecilication, in which drawing- Figure l represents a side view of myscrew. Fig. 2 is a central section of a portion thereof.

Similar letters indicate corresponding parts.

This invention relates to a nail or spike, with a screw-shank and with ahead, which is provided with teeth or prongs on its under edge or side,which, when the nail is driven into wood or other soft material, bite orsink into such wood, so as to lock the nail in position.

In the drawing, the letter A designates the nail or spike, the shank Bof which is provided with a spiral groove to increase itsbearing-surface. O is the nail-head, the under surface or face of whichis made concave, so as to form a tapering or inclined outer edge, whichis divided oi' into a number of parts, forming teeth or prongs a on theunder edge or on the side of the head. These teeth, therei'ore,have asharp point or edge, as also the web between each two of the teeth, andtheir direction is parallel to that of the spiral groove on the shank Bof the nail.

In using this screw-nail, a hole is iirst bored in the wood or othermaterial, to be secured or fastened in the saine manner as for anordinar)T screw.' My nail is then wedged or driven into this hole by ahammer in the same manner as an. ordinary nail. The teeth a ot' the headwill then readil)T sink or catch into the surface of the woodsurrounding the bore of the nail, so as to lock the same in position.The nail can hnow neither be turned or withdrawn without destroying, inwhole or in part,

JOSEPH LOVENSOHN.

\Vitnesses HERMANN BREIsMANN, GEORG PRILLWITZ.

